TWO tax officials named Fiddler and Till were arrested yesterday in the biggest anti-fraud operation ever carried out by Merseyside Police.

John Fiddler and Maria Till were among four women and seven men being questioned by detectives after arrests made mainly in the Huyton area.

The arrests were the culmination of a four-month investigation into an alleged plot to defraud the Inland Revenue of more than #400,000.

Fiddler and Till, both in their 30s, are Band E1 revenue officers - the second-lowest operational grade - working at the Bootle office.

The arrests were carried out in early morning raids as part of a joint operation by Merseyside Police and the Inland Revenue Board's investigation unit.

Last night, Detective Inspector Chris Hughes, the fraud squad officer leading the 62-strong investigation team, said: "We are delighted at the arrests and so are the Inland Revenue.

"This is the biggest operation we have ever had, both in terms of the amount defraud- ed and the number of officers involved in the investigation."

It is believed the investigation centres around claims that false employment details were used to produce tax rebates. Cheques ranging between #1,000 and #7,000 were allegedly sent out to addresses on Merseyside.

During yesterday's arrests, a sawn-off shotgun was recovered from one of the addresses in east Merseyside. Officers are planning to make more arrests in connection with the case in the near future.

Last night, the Inland Revenue refused to confirm whether any of its employees had been suspended.

A spokeswoman said: "At the moment, all we can confirm is that 11 people have been arrested as part of an ongoing criminal investigation in conjunction with Merseyside Police."

It is the second similar case in the past 18 months involving the Bootle centre, which processes millions of transactions every year.

Some observers of the tax system say that the disorganisation caused by the advent of self-assessment makes it easier for fraudsters to breach the normally tight Inland Revenue security systems. The usual modus operandi of the fraudsters is to use a colleague's computer without their knowledge to input a claim for a tax rebate. This is then paid automatically to the claimant.

In September, 2000, Inland Revenue employee Michael Dolan was jailed for three years for his part in swindling #123,000 from the taxman.

Liverpool Crown Court was told Dolan, 44, of Heathfield Road, Waterloo, gained #40,000 for his role in masterminding the fraud.

Gary Carragher, 46, of Hatherley Avenue, Crosby, was jailed for 12 months. Three other men received suspended prison sentences and five more were ordered to complete community service.